Generally, manufacturers of vehicles are required to purchase wheels from one supplier and tires from another supplier, or at best, one supplier or the other has to subcontract for the other component. Moreover, it is often necessary that either the tire or the wheel be manufactured to specifications to insure compatibility of the two components. In any event, purchasing costs, including higher freight costs, are maximized to the vehicle manufacturer, and hence, to his customers. In addition, the equipment manufacturer must include the costs of mounting the tires on the wheel in his overall manufacturing costs. It is obviously desirable to reduce the number of suppliers and to be able to procure a total assembly at less than the sum of the separate unit costs.
Further disadvantages of the conventional tire and wheel assembly reside in the occurrence of rim slippage, which reduces vehicle operation efficiency. Moreover, in some instances the excessive weight of a conventional wheel may be a significant factor, the alleviation of which would be a desirable end.
Others have recognized the advantage of providing a one-piece tire-wheel which is mounted on a central hub to be carried directly on the shaft of a vehicle. However, such tire-wheels are generally restricted to very small wheels, as for example, toys, children's carts, skates, and the like, and are often made fairly rigid to support loads without inflation. Where pneumatic tires are desirable, as on a vehicle driven by a human operator, considerable difficulty has been experienced in maintaining an air-tight enclosure where the tire is secured mechanically to a central hub. Difficulty has also been experienced in effecting a firm bond between the tire-wheel and the hub. In addition, when a one-piece tire-wheel extending from hub to crown, is inflated, there is a tendency for the tire to balloon excessively in lateral directions. This is particularly significant where there is a need to maintain dimensional stability in the tire-wheel assembly to avoid interference with other parts of the vehicle.